Dynamic Content

CSS Variable

--variable-name: value

Variable Usage


Counter Reset

counter-reset: name-of-counter

Counter Increment

counter-increment: name-of-counter

Counter Dynamic Value

content: counter(name-of-counter)

Attribute Dynamic Value

content: attr(name-of-attribute)

CSS Grid

Grid Template Columns

grid-template-columns: 40px 50px auto 50px 40px

Grid Template Rows

grid-template-rows: 25% 100px auto

Grid Template Areas

grid-template-areas: "a b c" | none

Grid Template

grid-template: "a a a" 20% "b b b" auto | 100px 1fr / 50px 1fr

Grid Column Gap

grid-column-gap: 10px

Grid Row Gap

grid-row-gap: 10px

Justify Items

justify-items: start | end | center | stretch

Align Items

align-items: start | end | center | stretch

Justify Content

justify-content: flex-start | flex-end | center | space-between | space-around | space-evenly

Align Content

align-content: flex-start | flex-end | center | space-between | space-around | stretch

Grid Auto Columns

grid-auto-columns: 100px | max-content | min-content

Grid Auto Rows

grid-auto-rows: 100px | max-content | min-content

Grid Auto Flow

grid-auto-flow: row | column | row dense | column dense

Grid Column Start

grid-column-start: 2 | areaname | span 2 | span areaname | auto

Grid Column End

grid-column-end: 2 | areaname | span 2 | span areaname | auto

Grid Row Start

grid-row-start: 2 | areaname | span 2 | span areaname | auto

Grid Row End

grid-row-end: 2 | areaname | span 2 | span areaname | auto

Grid Column

grid-column: 3 / span 2

Grid Row

grid-row: 3 / span 2

Justify Self

justify-self: start | end | center | stretch

Align Self

align-self: start | end | center | stretch

List Styling

List Type

list-style-type: disc | circle | square | none

List Position

list-style-position: inside | outside

List Image

list-style-image: url()

Box Properties

Box Sizing

box-sizing: border-box | content-box

Border Color

border-color: #2AA9E0


margin: 2px 4px 6px 8px | 0 auto

Border Style

border-style: none | hidden | dotted | dashed | solid | double | groove | ridge | inset | outset


padding: 2px 4px 6px 8px

Border Width

border-width: 10px


Background Image

background-image: url()

Background Color

background-color: #2AA9E0

Background Repeat

background-repeat: repeat-x | repeat-y | repeat | space | round | no-repeat

Background Attachment

background-attachment: scroll | fixed | local | initial | inherit

Background Position

background-position: top | right | bottom | left | center



position: static | relative | absolute | fixed | sticky

Clear Floating Elements

clear: none | left | right | both

Position Properties

top | right | bottom | left

Z Index

z-index: 3 | auto | inherit

Float Element

float: left | right | none

Text Styling

Font style

font-style: normal | italic | oblique

Vertical Alignment

vertical-align: baseline | 10px | sub | super | top | text-top | middle | bottom | text-bottom | initial

Space Between Characters

letter-spacing: normal | 4px

Text Align Last

text-align-last: auto | left | right | center | justify | start | end | initial | inherit

Font Family

font-family: 'Open Sans', sans-serif

Text Shadow

text-shadow: h-shadow v-shadow blur-radius color | none | initial | inherit

Font Variant

font-variant: normal | small-caps

Text Transform

text-transform: capitalise | lowercase | uppercase

Line Height

line-height: normal | 3em | 34%

Text Decoration

text-decoration: none | underline | overline | line-through

Text Justify

text-justify: auto | inter-word | inter-character | none | initial | inherit

Font Weight

font-weight: normal | bold | bolder | lighter | 100 - 900

Font Size

font-size: 12px | 0.8em | 80%

Horizontal Alignment

text-align: left | right | center | justify

Indent First Line

text-indent: 25px

Text Overflow

text-overflow: clip | ellipsis | string | initial | inherit

Pseudo Selectors & Elements

Mouse Over Selector

a:hover {}

Visited Links Selector

a:visited {}

Disabled elements selector

input:disabled {}

First Line Selector

p::first-line {}

Last Child Selector

p:last-child {}

First Element of its Parent Selector

p:first-of-type {}

After Element

.class::after {}

Active Link Selector

a:active {}

Link Selector

.class:link {}

Enabled elements selector

input:enabled {}

First Letter Selector

p::first-letter {}

Only Child Selector

p:only-child {}

Elements that have no Children Selector

p:empty {}

Focus Selector

input:focus {}

Checked elements selector

input:checked {}

Not a Specified Element Selector

:not(p) {}

First Child Selector

p:first-child {}

:nth-child Selector

p:nth-child() {}

Before Element

.class::before {}


Universal Selector

* {}

ID Selector

#id {}

Class Selector

.class {}

Type Selector

h1, h2 ,h3 {}

Adjacent Sibling Selector

h1 + p {}

Child Selector

ul > li {}

General Sibling Selector

h1 ~ p {}

Descendant Selector

p a {}

Attribute Selector

div[attribute="SomeValue"] {}


dplyr cheat sheet is a quick reference for dplyr that is a grammar of data manipulation, providing a consistent set of verbs that help you solve the most common data manipulation challenges.


A regular expression is a sequence of characters that specifies a search pattern.


PySpark is an interface for Apache Spark in Python. It not only allows you to write Spark applications using Python APIs


Go is a statically typed, compiled programming language designed at Google by Robert Griesemer, Rob Pike, and Ken Thompson.


Watchman exists to watch files and record when they change. It can also trigger actions (such as rebuilding assets) when matching files change.


Rollup Rollup is a module bundler for JavaScript which compiles small pieces of code into something larger and more complex, such as a library or application.


Bluebird is a fully-featured Promise library for JavaScript. The strongest feature of Bluebird is that it allows you to "promisify" other Node modules in order to use them asynchronously. Promisify is a concept applied to callback functions.


Flow is a static type checker for your JavaScript code. It does a lot of work to make you more productive. Making you code faster, smarter, more confidently, and to a bigger scale.

Node.Js Api

Node.js® is a JavaScript runtime built on Chrome's V8 JavaScript engine.

C Preprocessor

Quick reference for the C macro preprocessor, which can be used independent of C/C++.


Sass is a preprocessor scripting language that is interpreted or compiled into Cascading Style Sheets. SassScript is the scripting language itself. Sass consists of two syntaxes.


Active Admin is a Ruby on Rails plugin for generating administration style interfaces. It abstracts common business application patterns to make it simple for developers to implement beautiful and elegant interfaces with very little effort.


The Fetch standard defines requests, responses, and the process that binds them: fetching.


$ http POST http://example.com name="John" Host:example.com — JSON, cookies, files, auth, and other httpie examples.


RSpec is a computer domain-specific language testing tool written in the programming language Ruby to test Ruby code. It is a behavior-driven development framework which is extensively used in production applications.


Sauce Labs allows users to run tests in the cloud on more than 700 different browser platforms, operating systems, and device combinations.


Jasmine is a behavior-driven development framework for testing JavaScript code.


Sequelize is a promise-based Node.js ORM for Postgres, MySQL, MariaDB, SQLite and Microsoft SQL Server.


Ubuntu is a Linux distribution based on Debian and composed mostly of free and open-source software. Ubuntu is officially released in three editions: Desktop, Server, and Core for Internet of things devices and robots.

Rails Models

Ruby on Rails, or Rails, is a server-side web application framework written in Ruby under the MIT License. Rail is a model–view–controller framework, providing default structures for a database, a web service, and web pages.

Git Log

Git is software for tracking changes in any set of files, usually used for coordinating work among programmers collaboratively developing source code during software development.


Ruby on Rails, or Rails, is a server-side web application framework written in Ruby under the MIT License. Rails is a model–view–controller framework, providing default structures for a database, a web service, and web pages.

Ansible Examples

Ansible is an open-source software provisioning, configuration management, and application-deployment tool enabling infrastructure as code.

Bolt Quickstart

A quick guide to getting started writing Bolt tasks


RSpec Rails defines ten different types of specs for testing different parts of a typical Rails application.


rsync is a utility for efficiently transferring and synchronizing files between a computer and an external hard drive and across networked computers by comparing the modification times and sizes of files.

Ledger Cli

Ledger is a command-line based double-entry bookkeeping application. Accounting data is stored in a plain text file, using a simple format, which the users prepare themselves using other tools.


Homebrew is a free and open-source software package management system that simplifies the installation of software on Apple's operating system macOS as well as Linux.


Bundler provides a consistent environment for Ruby projects by tracking and installing the exact gems and versions that are needed.